1. Field of the Invention
The present invention relates to a field emission display (FED) device, and particularly, to an aging driving apparatus of a field emission display device and a driving method capable of preventing arcing by varying and applying a pulse over time in aging processing.
2. Description of the Background Art
In general, as an information processing system develops and is increasingly diffused, a display apparatus as a means for transmitting visual information is being importantly considered.
As a conventional display device, a CRT (Cathode Ray Tube) is disadvantageous in that it has a large volume and that an image display is distorted by an earth magnetic field.
Recent various display devices are aimed to have a large screen, a flat screen, a high brightness and high efficiency of a screen. Accordingly, studies of various flat panel display devices are actively proceeding. For example, as the flat panel display device, a liquid crystal display (referred to as “LCD) device, a plasma display panel (referred to as “PDP) device, a field emission display (referred to as “FED”) device and the like are developing.
Recently, wireless mobile communication such as IMT-2000 has been limelighted. A display device used for such wireless mobile communication requires a high speed, a low weight and small power consumption or the like. AS a representative switching device which can satisfy such requirements, there may be an MIM (Metal-Insulator-Metal).
In general, an MIM FED (Field Emission Display) device has a high-vacuum region for emitting an electron between an upper plate and a lower plate to which a high voltage is applied, that is, at a region between an anode and a cathode.
However, when a FED vacuum tube is manufactured to construct the high-vacuum region, a small amount of contaminants can be generated on surfaces such as emission elements, faceplates, gate electrodes, spacer walls or the like. Accordingly, when a field emission display device containing the contaminants is driven, electrons bombard the contaminants, and thus particles of the contaminants are knocked off from the surface.
Accordingly, when such phenomenon occurs, a high ionization pressure region is formed in a vacuum tube and thus emission of electrons is accelerated between a scan electrode and a gate electrode, and part of the emitted electrons is not emitted to an anode, but collides against the gate electrode, thereby overheating the gate electrode or having a bad effect upon forming a voltage difference between the gate electrode and an emitter electrode. Thus, when the gate electrode is overheated, a brightness discharge current beyond an energy gap between the emitter electrode and the gate electrode is formed, thereby causing a serious damage to the scan electrode and thus causing shortening of lifetimes of the field emission display device. Such a phenomenon is called arcing.
In order to prevent the arcing from occurring, contaminants in a panel should be removed and pressure in the panel should be lowered (that is, maintaining high vacuum).
As a method for removing contaminants of the conventional field discharge device in order to solve such problems, a getter which can absorb contaminants is included in a panel so as to absorb contaminants in driving of the field emission display device.
However, the method of absorbing contaminants by using the getter is disadvantageous in that a special process is needed. In addition, capacity of a getter is greatly different according to the size of a field emission display device, and in a state of reaching uppermost limit (that is, saturation), contaminants can no more absorbed.
In order to solve the problems generated in a use of the above-mentioned getter, recently, contaminants in a high-vacuum region are removed by an aging method using a DC voltage.
FIG. 1 is a graph illustrating a high voltage applied to an anode electrode over aging time according to the conventional art.
As shown in FIG. 1, for the conventional aging method, a method of separating contaminants attached to a surface of a high-vacuum region by applying a DC high voltage to an anode is used.
However, due to a DC voltage which gradually increases in the field emission display device, very high energy is charged in the field emission display device as time goes, and arcing frequently occurs due to a high field, thereby damaging the device and thus shortening lifetimes thereof.